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[45] [46] This model also suggests that metal ion adducts (e.g., [M+Na] + or [M+K] +) are mainly generated from the thermally induced dissolution of salt. [47] The matrix-assisted ionization (MAI) method uses matrix preparation similar to MALDI but does not require laser ablation to produce analyte ions of volatile or nonvolatile compounds. [48]
Dppf readily forms metal complexes. [2] The palladium derivative, (dppf)PdCl 2, which is popular for palladium-catalyzed coupling reactions, is prepared by treating dppf with the acetonitrile or benzonitrile adducts of palladium dichloride: [2] Substitution of the phenyl substituents in dppf leads to derivatives with modified donor-acceptor properties at the phosphorus atoms.
An important example is the issue of which matrix is used for MALDI spotting, since much of the energetics of the desorption/ionization event is controlled by the matrix rather than the laser power. Sometimes samples are spiked with sodium or another ion-carrying species to produce adducts rather than a protonated species.
The coupling of chromatography with MS is a well developed chemical analysis strategy dating back from the 1950s. Gas chromatography (GC)–MS was originally introduced in 1952, when A. T. James and A. J. P. Martin were trying to develop tandem separation – mass analysis techniques. [9]
Ammonium formate is commonly added in mass spectrometry to improve detection of certain analytes by the formation of analyte-ammonium adducts. A volatile organic acid such as acetic acid , or most commonly formic acid , is often added to the mobile phase if mass spectrometry is used to analyze the column effluents.
Adduct purification is a technique for preparing extremely pure simple organometallic compounds, which are generally unstable and hard to handle, by purifying a stable adduct with a Lewis acid and then obtaining the desired product from the pure adduct by thermal decomposition.
In organic chemistry, the Michael reaction or Michael 1,4 addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon.
Adducts may arise as a consequence of the chemical reaction between a given "physicochemical agent to which an organism is exposed across the lifespan" (sometimes referred to as the exposome). These physicochemical agents can be exogenous in origin, and include ionizing and non-ionizing radiation, the diet, lifestyle factors, pollution, and ...